#include "userlib.h"
#include <iostream>

using namespace std;

// 友元, 私有构造
class MySingleton : public Singleton<MySingleton> {
  friend class Singleton<MySingleton>;
  MySingleton() = default;

public:
  void msg() { cout << "MySingleton" << endl; }
};

int main(int argc, char **argv) {
  cout << "hello" << endl;
  MySingleton::get()->msg();
  dbgprint("dbgprint usage");
  return 0;
}
